CN1230102A - Biaxially corrugated flexible sheet material for absorbent articles - Google Patents

Abstract

The present invention relates to an absorbent article having a pair of opposing longitudinal edges and further comprising an absorbent assembly having an inner surface and an outer surface, a backsheet joined to the outer surface of the absorbent assembly. The backsheet includes a forming substrate including a first border region having a first surface pathlength and a second border region having a second surface pathlength, the first and second surface pathlengths preferably being measured while the forming substrate is in a relaxed state. The backsheet further includes an elongated region having at least a portion disposed between the first border region and the second border region, said elongated region including incrementally stretched regions which extend said elongated region in a first direction of elongation, the elongated region having a third surface path length measured when the forming substrate is in a relaxed state, the third surface path length being either greater than the first path length or greater than the second path length, thereby imparting a macroscopically three-dimensional configuration to the backsheet when in the relaxed state.

Description

Biaxially creped flexible sheet material for absorbent articles

The present invention relates to a shaped substrate capable of exhibiting a macroscopic three-dimensional configuration, and more particularly, to a flexible substrate having a three-dimensional configuration that can be used in both durable and disposable products, which Including, but not limited to, disposable absorbent articles such as disposable changing pads, incontinence garments, training underwear, menstrual sanitary garments, bandages, etc.

Babies and other incontinent people wear changing pads that absorb and hold urine and other body exudates. The function of the absorbent article is to contain the excreted substances and to isolate these substances from the wearer's body, the wearer's clothing and bed linen.

Disposable changing pads of the prior art are generally flat composite sheets which generally conform to the human body in a flat or corresponding geometrically folded shape to achieve a suitable "body shape". A major problem with prior art changing pads is that since the absorbent body is semi-rigid, the gap between the changing pad and the baby's body expands, especially after the changing pad has been used for a period of time. Such gaps can result in leakage of the disposable changing pad, thereby soiling or wetting clothing and bed sheets around the body.

One solution to the above problems is to use an elastomer in the leg openings of the changing pad to provide an improved fit and containment. An example of such prior art disposable changing pads is disclosed in US Patent 3,860,003, issued January 14, 1975 to Buell. Resilient changing pads of the type disclosed by Buell have been widely recognized and commercially successful, however, such flexible changing pads still have gaps and therefore leak from time to time.

A disposable changing pad that closely conforms to the contours of the wearer's body provides many advantages, including comfort, handling, storage, and the like. Due to the better conformability to body contours, absorbent articles utilizing the semi-elastic material of the present invention will fit closer to the body, thereby reducing the possibility of leakage of body exudates. In addition, absorbent articles utilizing the three-dimensional substrate of the present invention help reduce red marks on the skin due to the fact that it follows the contours of the body more closely because it reduces the excessive tension used to change the shape of the absorbent article.

The advantages of three-dimensional objects are achieved through the use of one or more shaped substrates. In general, such shaped substrates include elongated zones that are incrementally stretched to increase their surface pathlength, the substrate also includes border zones with shorter surface pathlengths, It is located near the elongation zone. The incrementally stretched elongated zone, together with the boundary zone, imparts a three-dimensional configuration to the substrate without additional force or elasticity. Therefore, the three-dimensional object is faster, easier and cheaper to manufacture than similar products currently on the market, thus reducing its overall cost.

It is an object of the present invention to provide an absorbent article comprising a formed substrate capable of assuming a macroscopic three-dimensional configuration.

A second object of the present invention is to provide an absorbent article having a topsheet and/or backsheet comprising a formed substrate capable of assuming a macroscopic three-dimensional configuration in a relaxed state.

A third object of the present invention is to provide an absorbent article having a topsheet and/or backsheet comprising a formed substrate capable of assuming a macroscopic three-dimensional configuration in a relaxed state without additional elastic forces.

The above and other objects of the present invention will be more clearly understood through the following descriptions made in conjunction with the accompanying drawings.

The present invention provides an absorbent article having a pair of opposed longitudinal edges, further comprising an absorbent assembly having an inner side and an outer side, a backsheet associated with the outer surface of the absorbent assembly. The backsheet comprises a formed substrate including a first border region having a first surface pathlength and a second border region having a second surface pathlength. Preferably, the first and second surface pathlengths are measured while the forming substrate is in a relaxed state. The backsheet also includes an elongated region located at least partially between the first and second border regions. The zones of elongation include incrementally stretched regions that elongate the zone of elongation along a first direction of elongation, the zones of elongation having a third surface pathlength that is obtained when the forming substrate is in a relaxed state. state, measured substantially parallel to the first direction of elongation. The third surface pathlength is greater than either the first or second pathlength so that the backsheet has a macroscopic three-dimensional configuration when the backsheet is in a relaxed state.

Although the claims summarize the description, it specifically indicates and defines the scope of protection of the present invention, but it is believed that the present invention will be better understood through the following descriptions made in conjunction with the accompanying drawings. , and similar reference numerals indicate similar elements.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an embodiment of a sanitary napkin of the present invention, with the backsheet facing the viewer, shown in a flat, uncontracted configuration.

Figure 2 is a perspective view of the sanitary napkin shown in Figure 1 showing a macroscopic three-dimensional configuration of the formed substrate.

Fig. 3 is a cross-sectional view of the sanitary napkin shown in Fig. 2 .

Figure 4 is a configuration of one embodiment of the formed substrate of the present invention in a relaxed state.

Figure 5 is a configuration of an alternative embodiment of the formed substrate of the present invention in a relaxed state.

Figure 6 is another embodiment of the formed substrate of the present invention in a relaxed configuration.

Figure 7 is a configuration of another alternative embodiment of the formed substrate of the present invention in a relaxed state.

Figure 8 is a configuration of another alternative embodiment of the formed substrate of the present invention in a relaxed state.

Figure 9 is an example of an incremental stretching system that may be used to form the incremental stretching zones of the present invention.

Figure 10 is another embodiment of an incremental stretching system that may be used to form the incremental stretching zones of the present invention.

Figure 11 is a plan view of a changing pad embodiment of the present invention, with the backsheet facing the viewer, showing a flat, uncontracted configuration.

Fig. 12 is a plan view of another urine pad embodiment of the present invention, with the backsheet facing the viewer, showing a flat, uncontracted configuration.

Figure 13 is a plan view of yet another urine pad embodiment of the present invention, with the backsheet facing the viewer, showing a flat, uncontracted configuration.

Figure 14 is a plan view of another urine pad embodiment of the present invention, with the backsheet facing the viewer, showing a flat, uncontracted configuration.

Figure 15 is a plan view of another changing pad embodiment of the present invention, with the backsheet facing the viewer, showing a flat, uncontracted configuration.

Figure 16 is a plan view of another changing pad embodiment of the present invention, with the backsheet facing the viewer, showing a flat, uncontracted configuration.

Figure 17 is a plan view of another changing pad embodiment of the present invention, with the backsheet facing the viewer, showing a flat, uncontracted configuration.

Figure 18 is a partial perspective view of one embodiment of a forming substrate of the present invention.

The term "absorbent article" as used herein means a class of articles which absorb and contain exudates from the human body, and in particular it relates to articles which are placed next to the wearer's body or It is placed near the wearer's body to absorb and contain various exudates from the body. The term "disposable", as used herein, refers to absorbent articles that, as an absorbent article, are not intended to be laundered or otherwise restored or reused (i.e., after a single use, they are will be discarded and preferably recycled, synthesized or otherwise disposed of in an environmentally friendly manner). "Integral" absorbent articles are those that are composed of separate parts that are combined to form a unified whole so that they do not require separate use parts such as separate supports and liners . Due to the disposable nature, low cost materials and manufacturing methods are especially important for disposable absorbent articles.

Although a formed substrate as described hereinafter in the present invention exhibits a macroscopic three-dimensional structure, it can be used as a backsheet for some disposable absorbent articles, such as disposable urine pads, feminine hygiene napkins, menstrual pads, incontinence pads, etc. Clothing, training pants, changing pad supports or liners, bandages and the like, however, the invention is not limited to such applications. In fact, the present invention can show great advantages in various occasions where a polymer film or sheet providing a macroscopic three-dimensional structure is required. Other examples of use of the present invention include packaging materials such as blister packs, liners or covers; shower caps and other personal hygiene products; bags; boxes; lids; tubes; condoms; straps; filters, etc. . By taking the backsheet of an absorbent article as an example, the detailed description of the preferred configuration and application of the present invention is sufficient to enable a person of ordinary skill in the art to apply the present invention to other applications.

A preferred embodiment of the unitary disposable absorbent article of the present invention is the catamenial pad, sanitary napkin 20 shown in FIG. As used herein, the term "sanitary napkin" means an absorbent article used by women near the vulva area, roughly outside the reproductive organs, to absorb and contain menstrual and other vaginal discharges from the woman's body ( such as blood, menstruation and urine). Inner labial devices, that is, devices that are partly inside and partly outside of the wearer's vagina, are also within the scope of the invention, where the term "vulva" refers to a device that is visible from the outside. female genitalia.

Fig. 1 is a plan view of a sanitary napkin 20 embodiment of the present invention, and it is in flattened state, and a part of its structure is cut away, so that show the structure of sanitary napkin 20 more clearly, and this sanitary napkin 20 faces away from wearing The user's part faces the viewer. As shown in Figure 1, the sanitary napkin 20 preferably comprises a liquid permeable topsheet 24, a liquid impermeable backsheet 26 connected to the topsheet 24, and an absorbent sheet positioned between the topsheet 24 and the backsheet 26. Component 25.

The sanitary napkin 20 has two surfaces, one is the surface in contact with the body, or is called "body-facing surface", and the other is the surface facing clothes, or is called "clothing-facing surface". The sanitary napkin 20 in Fig. 1 is viewed from its garment surface. Its body-facing side is worn near the wearer's body, while the garment-facing side is its reverse side, which is positioned near the wearer's underwear after the sanitary napkin 20 is used.

The sanitary napkin 20 also has two centerlines, a longitudinal centerline 100 and a transverse centerline 102 . As used herein, the term "longitudinal" refers to a line in the plane of the sanitary napkin, an axis or a direction that is generally aligned (e.g., generally parallel) with a vertical plane such that when the sanitary napkin 20 is in use, The aforementioned vertical plane bisects a standing wearer into left and right halves. Here, so-called "transverse direction" and "transverse direction" are interchangeable, and it refers to a line in the plane of the sanitary napkin, an axis or a direction, which is approximately perpendicular to the longitudinal direction (it will be worn Divided into two halves, anterior body and posterior body). Figure 1 also shows that the sanitary napkin 20 has a periphery 30 which is defined by the outer edges of the sanitary napkin 20, wherein the longitudinal edges are designated 32 and the end edges are designated 34.

In one embodiment of the sanitary napkin 20, the topsheet 24 and backsheet 26 have a length and width greater than the absorbent member 25 dimensions. The topsheet 24 and backsheet 26 may extend beyond the edges of the absorbent assembly 25, thereby forming the perimeter 30 of the sanitary napkin 20.

The absorbent article preferably comprises an absorbent component 25. In a preferred embodiment, the absorbent article 25 preferably includes an absorbent core 28 . The absorbent assembly 25 may comprise any type of absorbent core or any other absorbent element capable of absorbing and containing liquids such as urine and/or menses. The absorbent assembly 25 has an inner surface 29, an outer surface 27, and side and end edges. The absorbent assembly 25 can be made in various sizes and shapes (e.g., rectangular, hourglass, oval, dog-bone, asymmetrical, etc.), Various liquid absorbent materials, such as comminuted wood pulp, are commonly referred to as airfelt. Other examples suitable for use as absorbent materials include creped cellulose wadding; meltblown polymers including coforms; chemically hardened, modified, or cross-linked Cellulose fibers; synthetic fibers such as crimped polyester fibres; peat; tissue materials including tissue and tissue laminates; absorbent foams; absorbent sponges; superabsorbent polymers; absorbent gelling materials ; and any other similar materials and combinations thereof.

The shape and configuration of the absorbent assembly 25 and/or the absorbent core 28 can vary (for example, the absorbent core can have zones of varying thickness, a certain rate of change in hydrophilicity, or a lower average density and lower basis weight acquisition zone; Alternatively, one or more facing or structural layers may be included). In addition, the size and water-absorbing capacity of the moisture-absorbing component 25 can also vary to meet the needs of different wearers. The overall hygroscopic capacity of the hygroscopic component 25 should meet the requirements of the design load and the demand for the sanitary napkin 20 .

Exemplary absorbent structures that can be used as the absorbent assembly 25 of the present invention are given in U.S. Patent 4,610,678 issued September 9, 1986 to Weisman et al., and U.S. Patent 4,834,735 issued May 30, 1989 to Alemany et al. U.S. Patent 4,950,264 issued to Osbom on October 21, and European Patent Application 0198683 of the Procter & Gamble Company published on October 22, 1986 in the name of Duenk et al., each of which is used herein as refer to.

The backsheet 26 and topsheet 24 are preferably positioned adjacent the outer surface 27 and inner surface 29, respectively, of the absorbent assembly 25 and are preferably joined to each other by joining means (not shown) known in the art. For example, the backsheet 26 and/or the topsheet 24 may be secured to the absorbent assembly 25, either by a uniform continuous layer of adhesive, a patterned adhesive layer, an intermittent linear or spiral pattern of adhesive. Rows of lines, or dots of adhesive, connect them to each other.

A satisfactory binder is manufactured by the H.B. Fuller Company of St. Paul, Minnesota under the trade designation HL-1258. An example of a suitable connecting means includes an open pattern network of binder fibers as disclosed in US Patent 4,573,986, issued March 4, 1986 to Minetola et al., which is incorporated herein by reference. Another suitable connection method includes a pattern structure coiled by several long binder fibers, which was issued to Sprague, Jr. on October 7, 1975. US Patent 3,911,173; on November 22, 1978 to Zieker Apparatus and methods are disclosed in US Patent 4,785,996 to Werenicz et al.; and US Patent 4,842,666 issued June 27, 1989 to Werenicz. Each of the aforementioned patents is hereby incorporated by reference. In addition, the connection methods may also include thermal bonding, pressure bonding, ultrasonic bonding, dynamic mechanical bonding and any other suitable connection methods, or a combination of those known connection methods in the prior art.

The topsheet 24 is preferably compliant so that the wearer's skin feels soft and non-irritating. In addition, the topsheet 24 should be liquid permeable, allowing liquids (eg, menses, and/or urine) to easily pass through its entire thickness. Suitable topsheet 24 can be made of many different materials, such as woven and non-woven materials; polymeric materials, such as perforated thermoplastic films, perforated plastic films, hydraulic formed thermoplastic films; porous foams; reticulated foams; Reticulated thermoplastic film; thermoplastic tulle. Suitable woven and nonwoven materials may be composed of natural fibers such as wool or cotton fibres, synthetic fibers such as polymeric fibers such as polyester, polypropylene or polyethylene fibres, or a combination of natural and synthetic fibres. A preferred topsheet comprises an apertured film. Perforated films are suitable for making topsheets because they allow body exudates to pass through without absorbing them, thereby reducing the tendency of liquid to flow back and rewet the wearer's skin. In this way, the body-contacting surface of the formed film can be kept dry, reducing body soiling and improving wearer comfort. US Patent 3,929,135 issued December 30, 1975 to Thompson; US Patent 4,324,246 issued April 13, 1982 to Mullane et al; US Patent 4,342,314 issued August 3, 1982 to Radel et al; July 31, 1994 Formed films suitable for use are described in US Patent 4,463,045 to Ahr et al.; and US Patent 5,006,394 to Baird on April 9, 1991. Each of the aforementioned patents is hereby incorporated by reference. The preferred topsheet for use in the present invention is a formed film described in one or more of the above-mentioned patents and sold in the form of sanitary napkins produced by the Proct & Gamble Company of Cincinnati, Ohio under the name "DRI-WEAVE".

In a preferred embodiment of the present invention, the hydrophilicity of the topsheet 24 to the body surface helps liquid to pass through the topsheet 24 at a speed greater than that of the non-hydrophilic surface to the body surface, so that menstruation can be reduced. The possibility of liquid flowing off the topsheet rather than entering and being absorbed by the absorbent member 25. In a preferred embodiment, the topsheet is a formed film having incorporated a surfactant into the polymeric material of the formed film, as described in U.S. Patent Application Serial No. 08/072,660, which "Absorbent Article Having an Apertured Nonwoven Film Cover", Aziz et al., filed June 4, 1993, which is hereby incorporated by reference. Alternatively, the body surface of the outer cover can also be made hydrophilic by treatment with a surfactant, as described in U.S. Patent 4,950,260 issued August 21, 1990 to Osborn, which is used herein Reference.

Backsheet 26 among the present invention refers to the part away from wearer's skin in sanitary napkin 20, and it can prevent that the exudate absorbed and contained by absorbent core 28 wets those articles that contact with sanitary napkin 20, such as bed sheet and underwear. Therefore, the backsheet 26 is preferably impermeable to liquids (such as menses and/or urine) and is preferably made of a thin plastic film, although other soft liquid impermeable materials can also be used. As used herein, the term "soft" means that the material is compliant, readily conforming to the shape and contours of objects with which the material comes into contact. Accordingly, the backsheet 26 may comprise a woven or nonwoven material; a polymer film, such as a polyethylene or polypropylene film; a composite material, such as a coated nonwoven or a coated film comprising one or more perforated regions. Material. The backsheet is preferably a polyethylene or polypropylene film having a thickness of about 0.012 mm (0.5 mil) to 0.015 mm (2.0 mil). Examples of polyethylene films include P18-1401 produced by Clopay Corporation of Cincinnati, Ohio, and XP-39385 produced by Ethyl Corporation, Visqueen Division, of Terre Haute, Indiana. The backsheet 26 is preferably embossed and/or textured to provide a more cotton-like appearance. Additionally, the backsheet 26 may allow vapor to pass through the absorbent assembly 25 while preventing exudates from passing through the backsheet 26 (ie, breathability).

The backsheet 26 is preferably positioned adjacent the inside surface 29 of the absorbent assembly 25, and is preferably joined together by a suitable known attachment means. For example, the backsheet 26 is attached to the absorbent assembly 25 by a uniform continuous layer of adhesive, a patterned layer of adhesive, an intermittent linear or helical row of adhesive, or spots of adhesive. A satisfactory binder is manufactured by the H.B. Fuller Company of St. Paul, Minnesota under the trade designation HL-1258. Examples of suitable attachment means include an open pattern network of bonded fibers as disclosed in U.S. Patent 4,573,986 issued March 4, 1986 to Minetola et al., entitled "Waste Containing Disposable Garment" . Another suitable connection method includes a pattern structure coiled by several long binder fibers, which was issued to Sprague, Jr. on October 7, 1975. US Patent 3,911,173; on November 22, 1978 to Zieker Apparatus and methods are disclosed in US Patent 4,785,996 to Werenicz et al.; and US Patent 4,842,666 issued June 27, 1989 to Werenicz. Each of the aforementioned patents is hereby incorporated by reference. In addition, the connection method may also include thermal bonding, pressure bonding, ultrasonic bonding, dynamic mechanical bonding and any other suitable connection methods, or a combination of those known connection methods in the prior art.

In a preferred embodiment of the present invention, the backsheet 26 includes a formed substrate 80 . As used herein, "shaped substrate" refers to a substrate that is mechanically produced and which, in a relaxed state, assumes a macroscopic three-dimensional state and geometry. As used herein, a "relaxed state" refers to a state of a substrate or portion of a substrate in which the substrate is not subject to externally applied tensile forces. Such a shaped substrate 80 with a macroscopic three-dimensional structure has several advantages. When the formed substrate 80 is used as a backsheet in disposable absorbent articles such as urine pads or sanitary napkins, it can more easily conform to the shape of the wearer through its macroscopic three-dimensional configuration. Absorbent articles employing the formed substrate 80 of the present invention will provide a better fit since it will more easily conform to the shape of the wearer, thereby reducing the leakage of body exudates. In addition, absorbent articles incorporating the substrate of the present invention will reduce skin redness by better conforming to the shape of the wearer's body because the absorbent article reduces excessive tension.

molding base

FIG. 1 shows one embodiment of a forming substrate 80 of the present invention. The forming base 80 is shown in a macroscopically unshrunk configuration; a force is applied to the forming base 80 to stretch the base 80 into a relatively flat configuration (here, "Relatively flat" means that at least one surface of the object lies substantially in a plane). At least a portion of the forming substrate 80 includes incremental stretching. As used herein, the term "incremental elongation" or "incremental stretch" refers to a zone of intermittent mechanical stretching of the substrate, which has a plurality of small increments (incremental), which have been Stretched alone beyond the plastic yield point of the material, forming a permanent deformation.

The incremental stretch zones in the substrate can be formed using any suitable method. U.S. Patent to Weber et al. on September 1, 1992, entitled "Method of Gradual Stretching of a Laminated Open-Width (Web) Material with Zero Deformation, Imparting Elasticity Without Breaking the Web Material" 5,143,679, detailing some non-limiting examples of methods of forming incremental stretch zones, which is hereby incorporated by reference (although the aforementioned patent to Weber et al. is a method of incrementally stretching a laminated open web material , however, these methods can be used to stretch any suitable web material, including single-layer and multi-layer web materials, film laminates, etc.). The forming substrate 80 of the present invention may also be provided with incremental stretch zones by the method disclosed in U.S. Patent 5,518,801, issued May 21, 1996, to Chappel et al., entitled "Open-Width Materials With Elastic Behavior" .

As shown in Figures 1, 4-8 and 11-18, the forming substrate 80 preferably includes an elongated region 52, a pair of border regions 50, and a transition region 57 at least in part between the elongated region 52 and the border region. 50 (the transition region 57 is the region in the substrate 50 that has the characteristics of both the elongated region 52 and the boundary region 50). The elongated regions 52 include incrementally stretched regions 54 (incrementally stretched regions, which extend or are stretched along a first stretching direction 90, formed in the elongated regions 52. In a preferred embodiment, the first The boundary region 49 has a first surface pathlength 82, the second boundary region 51 has a second surface pathlength 84, and the elongated region 52 has a third surface pathlength 86, examples of which are shown in FIG. (Herein, the term "surface path length" means a dimension measured on the surface of the figure of the relevant area along a direction approximately parallel to an axis. "Approximately parallel" means axis-to-axis, Between, or the orientation relationship between the combination of axes and components, that is, the angle formed by the axes or components being compared is less than 45 degrees. "Substantially perpendicular" means between axes, between components and components, or between axes The orientation relationship between the bonded elements, that is, the axes or elements being compared form an angle greater than 45 degrees.) The surface path length of each element is preferably measured as follows.

Elongated region 52 is preferably partially located between boundary regions 49 and 51 and is incrementally stretched such that it has a longer relaxed surface path length than either or both of boundary regions 49 and 51 . The difference in path length gives substrate 80 a three-dimensional shape in its relaxed state, eliminating the need for elastomers. In certain preferred embodiments, it is desirable to attach the formed substrate 80 to another component of the absorbent article, which helps to maintain a three-dimensional configuration for the substrate. This ensures that the forming substrate 80 and thus the absorbent article have a three-dimensional shape. Otherwise, the article will force the forming substrate into a relatively flat configuration.

It should be noted that the boundary regions 50 may have any shape so long as at least a portion of each boundary region 50 is positioned adjacent at least a portion of the elongate region 52 . The transition zone 57 may be linear (FIGS. 4-6), or curved (FIGS. 7-8), continuous (FIGS. 4-8) or discontinuous (FIG. 5), or combinations thereof. Additionally, the forming substrate 80 can include a single, generally regular elongated region 52 , but the forming substrate 80 can also include more than one elongated region 52 . For example, the zone of elongation 52 may comprise a series of incrementally stretched "bubble" zones that are interconnected to cushion the infant's buttocks. Additionally, any zone of elongation 52 of the forming substrate 80 may include zones of different incremental stretches, or zones of several different types or directions of incremental stretching. As used herein, "differential incremental stretch" refers to an incremental stretch that imparts different shape and/or stretch properties to individual regions of the substrate. (In general, different regions comprising different incremental stretches have different surface pathlengths. However, in the described examples, the different incrementally stretched regions have the same surface pathlength.) Different incremental stretches Examples of quantitative stretching include (but are not limited to) regions of a substrate that have been subjected to more than one incremental stretching method with varying amounts of deformation within a single incremental stretching zone, Or there are different incremental stretch patterns in individual areas.

Border region 50 and elongate region 52 may be of the same or different materials. For example, the border region 50 preferably has some elasticity, while the elongate region 52 is substantially inelastic. Other properties preferably also vary, such as properties related to rigidity, flexibility, organization, hygroscopicity, water permeability, strength, color or aesthetics. One of the ways to provide different properties to different regions is to choose a substrate and induce different properties in the substrate by chemical, mechanical or other means. In a preferred embodiment, at least a portion of boundary region 52 may be hoop compressed or incrementally stretched, as described below.

The boundary zone 50 is separated from the elongated zone 52 by a transition zone 57 . In transition region 57 , the surface shape of forming substrate 80 undergoes a transitional change to accommodate the change in elongated path length from the surface path length in boundary region 50 to elongated region 52 . The width of transition region 57 may vary. Generally speaking, the wider the transition region 57 is, the smoother the transition between the boundary region 50 and the elongated region 52 will be. The transition between the boundary region 50 and the elongated region 52 is usually visible through a change in its surface morphology, but its identification requires microscopic investigation. Boundary line 56 is generally located at the center of the transition zone to orientate the measurement surface path length. An example of a boundary line 56 is depicted in FIG. 18 .

FIG. 18 is an enlarged perspective view of a portion of the substrate in one embodiment of a forming substrate 80 of the present invention in which, geologically speaking, the flat, unchanging surface of the boundary region 50 is transformed into a discontinuous or corrugated surface of the elongated region 52. Incrementally extruded surfaces. This transition occurs on the surface of a triangular end face, which triangle must exist in order for the surface to be continuous. Those of ordinary skill in the art will appreciate that other geometries are possible depending on the nature of the method by which the zones of elongation 52 are incrementally stretched.

Border region 50 may consist of a constant base, or may contain incrementally stretched regions. However, the superficial pathlength of the boundary region 50 should be less than the superficial pathlength of the elongated region 52 . In addition, the boundary region 50 can also be realized by using an elongated elastomer or other means, or itself has elastic, semi-elastic or plastic elongation properties. Alternatively, border region 50 may comprise a structurally elastic film material, as described below.

Measurement of Surface Path Length

"Surface path length" or "path length" means a length of a substrate, or any portion thereof, measured along the surface of the forming substrate 80 between the elongate region 52 and the boundary region, generally parallel to the boundary line 56 As shown in FIG. 18, it is measured on a portion of the forming substrate 80 under a tension-free condition. The surface path length is equal to the two opposite ends of the forming substrate when the substrate is sufficiently flattened without any tension in the forming substrate 80 and any geometric wrinkles, bends, or other "non-planar" structures are eliminated. The straight-line distance between the spaces. If the substrate is very flexible, as is common with substrate materials used in absorbent articles, it is usually stretched to a substantially flat state without any appreciable tension. However, it is clear to those of ordinary skill in the art that if the geometric folds, bends, or other "non-planar" structures are so rigid that tension must be applied to flatten them, other methods must be used. way to measure its surface path length. An example of measuring surface path length without flattening the substrate is disclosed in U.S. Patent 5,518,810, issued May 21, 1996 to Chappell et al., entitled "Open-Width Materials with Elastic Behavior," which is hereby is used as a reference.

For the simple geometric figures shown in Figures 1 and 11-14, wherein the boundary regions are straight and parallel to each other, the elongated region 52 is substantially uniformly elongated in a direction parallel to the boundary line 56. , then its surface path length is easier to measure. The boundary zone 50 is separated from the adjacent elongated zone 52 substantially along a boundary line 56 which divides the two zones. Then flatten each area as much as possible without introducing tension. Next measure the length of each component along boundary line 56 . The elongated region 52 should remove the transition region 57 between the boundary region 50 and the elongated region 52 . If the transition region 57 adjoins the elongated region 52 , the transition region 57 may cause difficulties in accurately measuring the surface path length of the elongated region 52 and/or the boundary region 50 .

For more complex geometries, an operation should be used that takes the influence of that geometry into account. If the forming substrate 80 is cut into several narrow strips along a direction parallel to the boundary region 50, the path length of the elongated region 52 can be easily measured without measuring the entire length. For example, when the boundary region 50 has a curved edge, the curved boundary line 56 between the elongated region 52 and the boundary region 50 can be divided into several segments so as to approximate a straight line. Straight lines perpendicular to the boundary line 56 are drawn in the boundary area 50 and the elongation area 52 respectively, so as to mark these divisional sections. The sum of the path lengths of each region (ie the sum of the path lengths of all segments measured approximately equidistant from the boundary line) is determined. When curved or irregularly shaped elements are encountered, it may be more convenient to use a linear axis representing an average value of the curved element.

The measurement method described above is useful for many substrates of the present invention, and it should be understood that the method can be varied to accommodate some of the more complex substrate materials within the scope of the present invention.

Method of making shaped substrate

Preferred methods of making the shaped substrate 80 of the present invention include, but are not limited to, methods by pressing of pairs of plates and rollers, thermoforming, high pressure hydroforming, or casting.

Preferably, an incremental stretching system is applied to the zone of elongation 52 of the present invention. A preferred incremental stretching system 300 is depicted in FIG. 10 . Incremental stretching system 300 preferably includes a pair of incremental stretching press rolls 302 and 304 . The pressure roller 302 includes a plurality of teeth 306 and corresponding grooves 307 separated by a toothless zone 316 which makes the boundary zone 50 . The pressure roller 304 includes a plurality of teeth 308 and corresponding grooves 309 extending along the entire circumference of the pressure roller 304 . The teeth 306 on the pressure roller 302 engage with the grooves 309 on the pressure roller 304 , and the teeth 308 on the pressure roller 309 engage with the grooves 307 on the pressure roller 302 . As a web material, such as web material 312, passes between incrementally stretching press rolls 302 and 304, web material 312 is stretched and/or elongated, creating incrementally stretched zones 314 such that The web material 312 is elongated in the cross-machine direction indicated by arrow 315 . Portions of the web material 312 that pass between the smooth toothless region 316 of the press roll 302 and the press roll 304 will be substantially undistorted, and they will form the border zone 50 . In order to form a desired structure, the specific shape, spacing, size, and overlap of relative teeth and grooves of the pressing rollers 302 and 304 can be adjusted.

Referring now to FIG. 9, an alternative incremental stretching system 350 is shown. Incremental stretching system 350 includes a pair of incremental stretching press rolls 352 and 354 . Press roller 352 includes smooth or grooved portions 355 and 356 spaced apart from each other on either side of tooth portion 357 . Likewise, press roller 354 also includes smooth or grooved portions 358 and 359 spaced apart from each other on either side of tooth portion 360 . Both teeth 357 and 360 preferably extend along the entire circumference of pressure rollers 302 and 304 . Thus, as a web material passes between press rolls 352 and 354, it deforms at discontinuities corresponding to locations 307 and 310, which engage each other so as to pass between press rolls 352 and 354. The 354 forms deformed and non-deformed regions in the material. This causes at least these portions of the web material to be stretched so as to elongate at least in the machine direction. The portion of material passing between smooth regions 355 and 359 and between smooth regions 356 and 358 will remain in its original state unless otherwise affected by other processes. The material subjected to processing in the press rollers 352 and 354 will produce two boundary regions 50, which are separated by the elongated region 52, which have deformed and undeformed regions, similar to the forming substrate 80 shown in FIG. .

In U.S. Patent 5,143,679, issued September 1, 1992 to Weber et al., entitled "Method for Zero-Deflection Gradual Stretching of a Laminated Open-Width Material, Imparting Elasticity Without Breaking the Open-Width Material," and in U.S. Patent 5,518,801, issued May 21, 1992 to Chappell et al., entitled "Open-Width Materials with Elastic Behavior," the method disclosed can be used as an example of another incremental stretching method, using To prepare the intermediate elongation region of the present invention, the above-mentioned literature is incorporated herein by reference.

The choice of incremental stretching method, and the choice of transition zone width and geometry can reflect an aesthetic choice, as well as the sensitivity of the material to sudden changes in path length, and the adaptation of the method used to prepare the substrate. characteristics, and other factors recognized by those familiar with the technical field. Furthermore, depending on the properties of the materials contained in the substrate, the forming substrate 80 may be sufficiently rigid so that it maintains a desired structure or geometry in the absence of any external force. Alternatively, the forming substrate 80 may also lack the rigidity to maintain its desired structural or geometric shape in the absence of external forces. In the embodiment of the sanitary napkin 20 shown in FIGS. An adhesive, such as the adhesive 60, that connects one of the components on the molding base 80 can impart necessary external force to the molding base 80, so that the molding base 80 can obtain and maintain a desired macroscopic three-dimensional structure or geometric shape.

While the process of incremental stretching, which generally stretches the forming substrate 80 in the machine direction or cross-machine direction, has been described above, it is understood that any portion of the zone of elongation 52, or any other portion of the forming substrate 80 Portions can withstand such incremental stretching even if the forming substrate 80, or any portion thereof, is elongated in directions other than the machine direction and the cross-machine direction. For example, incremental stretching can elongate the substrate, or any portion thereof, in a direction at any angle to the machine or cross-machine direction. (The direction of stretch in the complex patterns shown in Figures 5-8 can vary throughout the substrate.) It is also understood that incrementally stretched substrates or portions of the substrate can provide multiple elongation in one direction.

preferred embodiment

The sanitary napkin 20 shown in Figures 1-3 preferably includes a formed substrate 80 of the present invention. While the forming substrate 80 may comprise any one or several of the various elements of the sanitary napkin 20, in a preferred embodiment, the substrate 80 of the present invention is used as the backsheet 26, as described above. In this embodiment, the forming substrate 80 includes an elongated region 52 , at least two border regions 50 and a transition region 57 between the border region 50 and the elongated region 52 . In a preferred embodiment, the zone of elongation 52 includes an incremental stretch zone 54 which elongates the zone of elongation 52 in a direction generally parallel to the longitudinal axis 100 of the sanitary napkin 20 . The transition region 57 preferably also extends in a direction parallel to the longitudinal axis 100 . In a particularly preferred embodiment, the boundary regions 50 are substantially parallel to each other and are separated by at least a portion of the elongate region 52 .

A preferred sanitary napkin 20 has a pair of opposed longitudinal edges 32, and also includes a topsheet 24, a backsheet 26 connected to the topsheet 24, and an absorbent assembly positioned between the topsheet 24 and the backsheet 26. 25. The absorbent assembly 25 preferably has an inner side 29 and an outer side 27 . The topsheet 24 is preferably positioned adjacent to the inner side 29 of the absorbent assembly 25, while the backsheet 26 is preferably positioned adjacent to the outer side 27 of the absorbent assembly 25.

As shown in FIGS. 1-3, the backsheet 26 preferably includes a forming substrate 80 having an elongated region 52, two border regions 50, a first border region 49 extending approximately parallel to each longitudinal edge 32 and a The second boundary area 51 . The width B of each boundary region 50 is preferably between about 0.1 cm-3.0 cm. The width B of the boundary area 50 is preferably between 0.2 cm and 1.5 cm. Border regions 50 are preferably spaced between 1.0 cm and 30.0 cm apart. More preferably, the boundary regions 50 are separated by 2.0cm-15.0cm. The boundary area 50 is optimally separated by 4.0cm-10.0cm. It has also been found that the spacing between the border region 50 and the longitudinal edge 32 of the sanitary napkin 20 can affect the performance of the absorbent article. Accordingly, the spacing between the border region 50 and the longitudinal edge 32 of the sanitary napkin 20 is preferably between about 0-50 mm, more preferably 1-30 mm, and most preferably 2-5 mm.

Between each boundary region 50 and the elongated region 52 there is preferably a transition region 57. The zones of elongation 52 preferably include zones of incremental stretching 54 which form zones of elongation 52 extending in a first direction of stretch 90 . The first boundary region 49 preferably has a first surface pathlength 82, the second boundary region 51 has a second surface pathlength 84, and the elongated region 52 has a third surface pathlength 86, as shown in FIG. The first surface pathlength 82 and/or the second surface pathlength 84 are less than the third surface pathlength 86 of the elongated region 52 when the forming substrate 80 is in the relaxed state. In some preferred embodiments, the third surface pathlength 86 of the elongated region 52 may be 5% to 500% greater than the first and second surface pathlengths 82 and 84 of the boundary region 50 . The surface path length of the elongated region 52 is better than the surface path length of the boundary region 50 by 10%-250%, and the surface path length of the elongated region 52 is 20%-100% larger than the surface path length of the boundary region 50. . This ensures that the elongate region 52 adjoining the boundary region 50 imparts a macroscopic three-dimensional structure to the backsheet 26 when the substrate is generally in a relaxed state.

Another preferred embodiment of the absorbent article may comprise two or more formed substrates. In one embodiment, the topsheet 24 may include a forming substrate, such as forming substrate 80 . Additionally, as noted above, any shaped substrate may include regions of differing extensibility.

11-17 are plan views of another embodiment of a diaper according to the present invention in a flattened, uncontracted state (relaxing of the elasticity that would cause contraction), with the portion of the diaper 40 facing away from the wearer facing away from the wearer. viewer. (Herein, the so-called "diaper pad" refers to absorbent articles generally used by babies to absorb and store body exudates. However, such absorbent articles are not limited to those articles for babies, and can also Including incontinence products for adults, training pants, menstrual underwear and the like.) The changing pad 40 preferably includes a liquid permeable topsheet 24; The topsheet 24 is connected to the topsheet 24 and an absorbent core 28 is located between the topsheet 24 and the backsheet 26. Each urine pad 40 preferably has a front waist region 70, a rear waist region 74, and a crotch region 72 extending between the front waist region 70 and the rear waist region 74. In addition, the urine pad 40 preferably also has longitudinal sides 32 and end sides 34 .

Figures 11-17 illustrate some preferred embodiments of a urine pad 40 in which the length and width of the topsheet 24 and backsheet 26 are generally greater than the dimensions of the absorbent member 25. The topsheet 24, backsheet 26, and absorbent assembly can be assembled in a variety of configurations as is well known. The changing pad 40 may also include other components such as elastic sides; elastic leg cuffs; elastic waist features; fastening systems and others known in the art. In U.S. Patent 3,860,003, issued January 14, 1975 to Kenneth B. Buell, entitled "Constricting Sides for Disposable Changing Pads"; issued September 29, 1992 to Kenneth B. Buell, entitled Some preferred exemplary disposable changing pad configurations are disclosed in US Pat. No. 5,151,092, "Absorbent Article with Dynamic Elastic Waist Feature with a Preset Elastic Flexure Pivot", which is incorporated herein by reference. U.S. Patent 4,846,815 issued to Scripps on July 11, 1989; U.S. Patent 4,894,060 issued to Nestegard on January 16, 1990; Some exemplary fastening systems are disclosed in Patent 3,848,594; US Patent 4,662,875, issued May 5, 1987 to Hirotsu, which are incorporated herein by reference.

As shown in FIGS. 11-17, each changing pad 40 preferably includes at least one formed substrate 80. As shown in FIG. In the depicted embodiment, the forming substrate 80 is incorporated into the backsheet 26, however other embodiments are shown wherein the forming substrate 80 is incorporated into any number of other elements of the urine pad 40. In the illustrated embodiments, the forming substrate 80 includes an elongated region 52 , at least two border regions 50 , and a transition region 57 between each border region 50 and the elongated region 52 . As shown in FIG. 11 , the elongated region 52 can be elongated along at least one direction generally parallel to the transverse axis 112 of the urine pad 40 and, as shown in FIG. 12 , along at least one direction generally parallel to the longitudinal axis 110. , or elongate in multiple directions, as shown in Figure 13. The direction of extension of the transition region 57 is preferably substantially parallel to the direction of extension of the elongate region 52 . In a particularly preferred embodiment, as shown in FIGS. 11-14 , the urine pad 40 has at least two boundary regions 50 , namely a first boundary region 49 and a second boundary region 51 . The first boundary region is preferably parallel to the second boundary region and separated by at least a portion of the elongated region 52 .

The embodiment shown in FIGS. 13-14 includes at least one pair of border regions 50 surrounding at least a portion of the elongate region 52 . In this embodiment, there are preferably two boundary regions 50 that are approximately parallel to each other. Another non-limiting embodiment includes three or more border regions 50 which may surround at least a portion of the elongate region 52 . Yet another embodiment includes the boundary region 50 generally forming a rectangle, ring, ellipse, trapezoid, hexagon, and diamond, some of which are shown in FIGS. 15-17.

Border region 50 may be of any shape and any size. As shown in FIG. 11 , the boundary region 50 may generally include the front and rear waist regions 70 and 74 of the urine pad 40 . In a typical medium-sized baby changing pad, the border regions 50 may be spaced 1-40 inches apart, preferably 2-30 inches apart, most preferably 3-22 inches apart. Additionally, at least a portion of the border region 50 may be a narrow strip extending along the longitudinal edge 32 of the urine pad 40 . In this configuration, an embodiment of which is shown in FIG. 13 , a portion of the border region 50 extends along the longitudinal edges of the urine pad 40, preferably with two edges substantially parallel, and preferably within 1/2 of the width. Between 32 inches and 1 inch; the width of a portion of the border area 50 is preferably between 1/16 inch and 3/4 inch, and most preferably between 1/8 inch and 1/2 inch.

The distance of the border region 50 from the longitudinal edges of the absorbent core 28 is preferably 0-10 inches, most preferably 1/8-8 inches. It should be noted that, in some embodiments, the distance between the boundary region 50 and the longitudinal edge 32 can vary along the length of the longitudinal edge 32 or along the two sides of the urine pad 40 .

In preferred embodiments, the elongated region 52 may have a surface pathlength that is about 5%-500% greater than the surface pathlength of the boundary region 50; more preferably 10%-250% greater; greater than 20% -100% best.

As shown in FIG. 13, the urine pad 40 may include a backsheet 26 having a formed substrate 80 with its extensible regions 52 stretched in multiple directions. It should be noted that the number of elongation directions of the elongated regions 52 is not limited, but when the substrate 80 is in a relaxed state, the surface path length of at least a part of the elongated regions 52 along the transition region 57 must be greater than the surface of the boundary region 50. path length. Furthermore, the amount of elongation in the elongated zones 52 can vary, and there can be more than one elongated zone 52 in the same absorbent article. FIG. 14 shows an embodiment of a urine pad 40 having a zone 53 of different incremental stretch. As noted above, "differential incremental stretching" means that the incremental stretching means have specific base regions that have different shape and/or elongation characteristics. The zones of differential incremental stretch 53 can create a pocket for body exudates, or provide an improved fit.

In using the changing pad 40, preferably a waist region, preferably the rear waist region 74, is placed on the back of the wearer. The other portion of the pad 40 is then pulled between the wearer's legs so that another waist region, preferably the front waist region 70, traverses the front of the wearer. Then the side panels of the urine pad 40 are wrapped around the waist of the wearer and the rear waist region 74 is fastened to the front waist region 70 on each side of the wearer to form a waist closure on each side of the wearer. body.

The specific embodiments of the present invention have been described and explained above. It is obvious to those skilled in the art that various improvements and changes can be made without departing from the principles and protection scope of the present invention. All improvements and changes falling within the scope of the present invention are intended to be included within the scope of the appended claims.

Claims (10)

1. an absorbent device has a pair of mutual opposed longitudinal edge, and this absorbent device comprises:

An absorbent assemblies, it has an inner surface and an outer surface, preferably also comprise a top flat, an egative film that links to each other with above-mentioned top flat, also has the absorbent article core between described egative film and described top flat, described top flat comprises at least a portion of described absorbent assemblies inner surface, and described egative film is positioned near the outer surface of absorbent assemblies;

An egative film links to each other with the outer surface of absorbent assemblies, and this absorbent device is characterised in that described egative film comprises the molding substrate, comprising:

(a) one first frontier district, it has a first surface path; With one second border

The district, it has a second surface path, and described first and second surface-pathlength are

When being in relaxed state, the molding substrate measures; And

(b) elongation zone, it to small part between described first and second frontier districts, described

The elongation zone comprises the increment type stretch zones, and these zones make described elongation zone along first prolonging direction

Elongation, the elongation zone has one the 3rd surface-pathlength, and this surface-pathlength is in the molding substrate

When being in relaxed state, be roughly parallel to that described first prolonging direction measures, the 3rd surperficial path

Length is greater than in described first and second paths one or any one, thereby at egative film

When being in relaxed state, this egative film has a kind of macroscopical 3-d modelling.

2. a sanitary towel has a pair of mutual opposed longitudinal edge, and this sanitary towel comprises:

A top flat; An egative film that links to each other with described top flat; And absorbent assemblies between described top flat and egative film, this absorbent assemblies has an inner surface and an outer surface, described top flat is positioned near the inner surface of absorbent assemblies, and described egative film is positioned near the outer surface of described absorbent assemblies;

This sanitary towel is characterised in that its egative film comprises a molding substrate, comprising:

(a) be roughly parallel to first frontier district that described longitudinal edge extends, in the described frontier district one

Have a first surface path, second frontier district has a second surface path, and is described

First and second frontier districts are roughly parallel to described longitudinal edge and extend described first and second

Surface-pathlength is measured when the molding substrate is in relaxed state, and each frontier district is tool all

A width is arranged, be approximately 0.1-3.0cm, more preferably between about 0.2-1.5cm,

Spacing between the described frontier district is between about 1.0-30.0cm, even more preferably approximately

2.0-15.0cm between, most preferably approximately between the 4.0-10.0cm; And

(b) local at least elongation between described first frontier district and described second frontier district

The district, described elongation zone comprises the increment type stretch zones, these zones make described elongation zone along first

The prolonging direction elongation, the elongation zone has one the 3rd surface-pathlength, and this length is in the molding substrate

When being in relaxed state, be roughly parallel to that described first prolonging direction measures, the 3rd surperficial path

Length is greater than in described first, second path one or any one, thereby at egative film

When being in relaxed state, make this egative film have a kind of macroscopical 3-d modelling.

3. as the described absorbent device of above-mentioned arbitrary claim, it is characterized in that, described first and second frontier districts are roughly parallel to described longitudinal edge and extend, described first prolonging direction is roughly parallel to described longitudinal edge, perhaps described first and second frontier districts are approximately perpendicular to described longitudinal edge extends, and described first prolonging direction is approximately perpendicular to described longitudinal edge.

4. as the described absorbent device of above-mentioned arbitrary claim, it is characterized in that, described top flat comprises the second molding substrate, this substrate comprises one first frontier district and one second frontier district, they are parallel to described longitudinal edge respectively extends, and described first frontier district has a first surface path, and described second frontier district has a second surface path, when described molding substrate is in relaxed state, first and second surface-pathlength is measured; An elongation zone is between described frontier district, described elongation zone comprises the increment type stretch zones, these zones make described elongation zone extend along first prolonging direction, the elongation zone has one the 3rd surface-pathlength, this length is when the molding substrate is in relaxed state, be roughly parallel to that described first prolonging direction measures, the 3rd surface-pathlength or greater than described first via electrical path length, perhaps greater than the described second path degree, thereby when top flat is in relaxed state, make this top flat have a kind of macroscopical 3-d modelling.

5. as the described absorbent device of above-mentioned arbitrary claim, it is characterized in that described molding substrate comprises some different increment type stretch zones.

6. as the described absorbent device of above-mentioned arbitrary claim, it is characterized in that described first and second frontier districts have elasticity.

7. as the described absorbent device of above-mentioned arbitrary claim, it is characterized in that, comprise at least three frontier districts, promptly described first and second frontier district and one the 3rd frontier district.

8. as the described absorbent device of above-mentioned arbitrary claim, it is characterized in that described frontier district is surrounded at least a portion elongation zone fully.

9. as the described absorbent device of above-mentioned arbitrary claim, it is characterized in that described elongation zone has the increment type stretch zones, this increment type stretch zones makes the elongation zone in described first prolonging direction and at least one other prolonging directions elongation.

10. as the described absorbent device of above-mentioned arbitrary claim, it is characterized in that described top flat comprises the second molding substrate, it comprises one first frontier district and one second frontier district, they are respectively perpendicular to described longitudinal edge, described first frontier district has a first surface path, described second frontier district has a second surface path, and these two surface-pathlength are all measured when the molding substrate is in relaxed state; An elongation zone is between described frontier district, described elongation zone comprises the increment type stretch zones, these zones make described elongation zone extend along first prolonging direction, the elongation zone has one the 3rd surface-pathlength, this length is when the molding substrate is in relaxed state, be roughly parallel to that described first prolonging direction measures, the 3rd surface-pathlength is wanted or greater than first via electrical path length, perhaps greater than second path, thereby when top flat is in relaxed state, make this top flat have a kind of macroscopical 3-d modelling.

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